From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754406AbcL3PC4 (ORCPT ); Fri, 30 Dec 2016 10:02:56 -0500 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:61527 "EHLO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754109AbcL3PCy (ORCPT ); Fri, 30 Dec 2016 10:02:54 -0500 From: "Rafael J. Wysocki" To: Linux PM Cc: Srinivas Pandruvada , LKML Subject: [PATCH 2/3] cpufreq: intel_pstate: Use locking in intel_cpufreq_verify_policy() Date: Fri, 30 Dec 2016 15:57:11 +0100 Message-ID: <2958352.e0VhhpxTVR@aspire.rjw.lan> User-Agent: KMail/4.14.10 (Linux/4.10.0-rc1+; KDE/4.14.9; x86_64; ; ) In-Reply-To: <5344750.TOCWYON8QY@aspire.rjw.lan> References: <5344750.TOCWYON8QY@aspire.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki Race conditions are possible if intel_cpufreq_verify_policy() is executed in parallel with global limits updates from sysfs, so the invocation of intel_pstate_update_perf_limits() in it should be carried out under intel_pstate_limits_lock. Make that happen. Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 4 ++++ 1 file changed, 4 insertions(+) Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -2157,8 +2157,12 @@ static int intel_cpufreq_verify_policy(s if (per_cpu_limits) perf_limits = cpu->perf_limits; + mutex_lock(&intel_pstate_limits_lock); + intel_pstate_update_perf_limits(policy, perf_limits); + mutex_unlock(&intel_pstate_limits_lock); + return 0; }